: Active-low input controlling the output drivers during read cycles. 27 Write Enable : Active-low input triggering a write sequence. 28 VCCcap V sub cap C cap C end-sub Power Supply : +5V input. Common ECU Failure Modes & Diagnostics
The (often cross-referenced with the full part number D43256BGU-70Y ) is a specialized automotive memory and driver integrated circuit (IC) widely utilized within Bosch engine control units (ECUs) , including EDC16 diesel engine computer boards . Tracking down the NEC B58944 datasheet is a common necessity for automotive electronics technicians and engineers performing ECU repair, component cloning, or reverse-engineering of vehicle engine modules. Because this chip is a proprietary or custom-masked part originally produced for Bosch by NEC, standard commercial semiconductor datasheets can be difficult to find through traditional retail channels.
These distributors are your best bet for finding authentic, new-old-stock (NOS) components, though they may require bulk orders and have a more formal procurement process.
The is a 28-pin Small Outline Package (SOP-28) dual-channel solid-state relay controller, or more broadly, an integrated driver IC optimized for high-side switching in automotive environments. nec b58944 datasheet 2021
Since an official version was never released (NEC's semiconductor division was transferred to Renesas in 2010, and most legacy datasheets were archived by 2015), the following parameters are aggregated from:
: 70 nanoseconds ( -70Y suffix indicates speed grading and temperature profiling).
Used in various ME-series control modules (e.g., ME7.9.6, ME7.5). : Active-low input controlling the output drivers during
The NEC B58944 is a medium power NPN silicon transistor, commonly used in various applications such as AF amplifier, HF amplifier, and other general-purpose amplifier circuits.
Engine stalling, cylinder misfire, or failure of specific actuators to operate (e.g., fuel pump, fan).
Because it is an SOP-28 SMD component, replacement requires skilled surface-mount soldering techniques (hot air station recommended). Common ECU Failure Modes & Diagnostics The (often
15 dedicated lines to address the 2152 to the 15th power (32,768) distinct 8-bit memory locations.
Note: While specific "2021" datasheets are often reproductions of original documentation, industry suppliers in 2021 highlighted these key features for the B58944: 1. Dual-Channel High-Side Switching
: Preheat the ECU board to roughly 100°C–120°C to facilitate easier solder liquefaction without blistering the multilayer PCB.
